The present invention relates to a coupling between a driving wheel flange and an output member of a transmission joint.
In a classic arrangement, the output member of a joint is formed by a bell housing of a constant-velocity joint extended from an integrally-formed splined wheel stub axle. To provide coupling, the stub axle is forcibly inserted into a broached bore in the flange and secured by a nut screwed onto a threaded end portion of the stub axle.
However, such an arrangement has a number of drawbacks. The stub axle must be of an extended length to pass through the wheel flange creating difficulty during transmission disassembly and increasing the weight of the rotating assembly supported by the rolling-contact bearing. Thus, it is often necessary to dismantle almost all of the vehicle power train in order to replace one of the constituent parts. Further, the forcible insertion of the stub axle into the broached bore in the wheel flange leads to swelling of the latter, which detrimentally effects the prior bearing adjustment and decreasing reliability.
In another known arrangement, the stub axle is dispensed with and the complementary coupling means include frontal splines at the end of the flange facing the bell housing of the constant-velocity joint. The splines interact with complementary frontal splines on the bell housing which is then secured by a screw which passes through the flange bore.
However, as the frontal splines are formed on a circle having a small radius, the contacting spline flanks must be inclined in order to avoid the splines being destroyed under the effect of torque. Thus, the flange is stressed in an undesirable axial manner during driving which tends to separate the flange from the constant-velocity joint.
Another solution has been proposed in document FR-A-2 605 557, especially in the embodiment described with reference to FIG. 4 which consists of a rotational coupling between a driving wheel flange and a transmission joint output member. The wheel flange rotates within a wheel support rolling-contact bearing having an inner race assembly integral with the wheel flange. The wheel flange and the output member of the joint are coupled through a ring attached to the end of the flange facing the output member and integral with the inner race assembly. The ring includes driving profiles designed to interact with complementary profiles integral with the output member distributed outwardly of the extension end of the wheel flange bearing the ring.
However, this solution also has drawbacks. In particular, the driving connection between the inner race of the bearing and the flange is achieved by complementary splines which are formed just at the end of the flange. Such an arrangement requires the flange to be extended substantially beyond the moving bodies of the bearing so as to allow the driving connection to be established. The result is that the center of the joint is an unacceptable distant from the bearing thereby increasing the overall size of the joint. In addition, the distance between the center of the joint and the bearing limits the turning angle of the vehicle on which the device is mounted.